Let-off for narrow-ware looms



Dec. 30, 1930. r E. R. HOLMES 1,786,557

LET-OFF FOR NARROW WARE LOOKS Filed Dec. 5, 1929 I N VEN 7-01-1 E1. BR/DGERHULJMES M-u-p w z' A TTUFPNEY Patented Dec. 30, 1930 r I UNITED STATES PATENT-1 OFFICE .nLBRIneE 3. HOLMES, or WORCESTER,MASSACHUSETTS, Assrenon To CROMPTON & KNOWLES LOOM WORKS, or WORCESTER,MASSACHUSETTS, A CORPORATION or MASSACHUSETTS LET-era FOR NARnow-wAnn Looms Application filed December 5, 1929. Serial-No. 411,892

This invention relates to improvements in let-offs for narrow ware looms and it is the general object of the invention toprovide a si'mplifiedlet-olf of the gravity actuated type 5 wherein the release of the tension will not be abrupt but'will be gradual to preserve a uniform tension on the warp threads.

In certain forms of narrowware looms it is customary to trainthe warp threads extending from the warp spools or beams under a movable weighted pulley arrangedto move upwardly as the warp is consumed in the weaving operation. A disk movablebetween friction pads is sometimes employed in this 5 form of let-off, oneor another of the pads being under control ofa-le ver lifted by the pulley as thelatter rises. In certain forms of this general type'of let-off heretofore employed it is possible for-the releasing pad because of the location of the. center around which it moves to Stick, thereby preventing paying-01f of the warp and resultantbreaking of the latter. It is an importantobject of my present inventionto provide such an arrangement between'the pad and the lever as will efiect 'proper'release of the tension.

It is a more particular object of my present invention to provide a'friction pad carrying pivoted member to cooperate with the pulley actuatedlever ,whereinfyielding meansbei tween the lever and the member act so that the latter will not move to cause a sudden release of. the tension.

. With these and other objects in View which set forth inthe claims. f

Y In the accompanying drawingswherein a convenient embodimentof my invention is set forth, I

Fig. 1 is an end elevation of the upper Each pulley stock has eXtending there-:

will appear as the descriptionfproceeds,my invention resides in the combination andv ar- 7 rangement of parts hereinafter descrlbed and Fig.2 is a horizontal'section on an enlarged Fig. 5 .is a detail vertical section on an en- I larged scale on line 55 of Fig. 4.

Referring particularly to Fig. 1, I have shown a loom frame lOhaving secured thereto a top rigging 11 provided with upper and 1 lower Stands 12 and 13, respectively, between which extends a supportingcarrier or bracket 14 provided with a plurality of rearwardly extending rods or spindles 15. Thelatter have mounted thereonwarp spools '60 16 and the warp threadsare led upwardly from said spools around guides 17 and 18,

respectively. The warp extendsndown from each guide 18 under apulley 19 and then up over one or more rollers 20 from which they 1 descend toipass under what in effect is awhip roll21. I f

Each pulley 19' is mounted on a so-called pulley stock 22 and carries a, 1 weight 23.

.70 through a lever 24 and as the warp is used up the pulley: stock will be'raised to lift. the

acts'to permit the paying-off of additional 3 warp so that the weight and pulley stock may.

again descend. r

The matter thus far described is common construction, the pulley stock being substantiallythe same as setforth in my prior Pat: 80 cut No. 1,280,734 and the lever arrangement may be similar to that shown in my prior Patent N 0. 1,546,582 which shows a disk similar to that designated herein at 25 to be detachably connected tothe correspondingififi spool and rotate with the latter; 1 1

In carrying my invention into effect I provide a series of pressed steel brackets one ofwhich isshown in detail in Fig. 2 at, 30. Each bracket is secured to'the carrier 14 by" means of bolts 31 and supports a horizontally extending stud 32. y The stud has pivotally mounted thereon a member 33 ha'vinga horizontally extending arm 34 which in effect is a saddle U-shaped in section as shown in Fig. 5. Each of the levers 24 is pivotedon. the stud 32 and passes through the saddle, being adapted to have. engagement with thelower horizontal web 35 of the latter.

The member or lever 33 is provided withimo a depending arm 36 to which is secured the movable friction element 37, which may be a strip of leather 37. The latter has contact with one face of the disk 25 and moves the latter against the fixed friction pad 38 which is secured to the bracket 30.

Extending from the member 33 is a small finger 39 between which and lever 24 is located a comparatively light compression spring 40. The latter is held. in position by means of bosses or lugs &1 and 42 carried, respectively, by the arm 39 and lever 24 so as to prevent loss. Any other convenient means of retaining the spring in position may be employed.

In operation it may be assumed that an abundance of warp has been unwound from the spoils so that the pulleys 19 are in a rel atively low position with the weight 28 supported by the outer end of the lever 2%. Under these conditions the let er will overpower spring 40 and act through lever to push pad 37 against the disk to prevent further paying-off of the warp. As Weaving progresses and the warp is used up the pulley stock 22 will be raised and in time will lift the lever 24- away from the web At this time the compression spring 40 comes into play and exerts a downward pressure on the horizontal portion of the member 33, tending to hold the pad 37 against the disk 25. As the lever continues to move upwardly the effect of the spring gradually grows less and less until the pressure of the pad 30 is so light as to permit slipping of the disk, whereupon the spool which is caused to rotate with the disk can unwind warp and the pulley 19 will again move downwardly to restore the parts to disk locking position. v

I find that it is of considerable importance to have the stud 32 around which the pad moves as near the disk 35 as possible. It is not essential, however, that the spring 40 be used, although its use results in a some what smoother action on the part of the disk and friction pads.

From. the foregoing it will be seen that I have provided a simple form of let-elf wherein the weighted lever and the movable fricti on member are pivoted about the same stud, the member being formed to have engaging relation with the lever when the latter is down. Furthermore, it-will be seen that the spring 40 which is shown herein for convenience as a compression. spring prevents a sudden releas in the friction exerted by the mov able pad when the lever moves away from the web The weight of the lever is sufficient to overpower the spring 40 under ordinary conditions so that as soon as the lever moves away from the web the friction will be reduced an appreciable amount although not entirely so, and the diminution in pressure will be gradual as the lever moves upwardly.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be li1nited to the details herein disclosed, but what I claim is:

1. In a let-off for a narrow Ware loom having a warp spool and a disk movable therewith and a friction element to cooperate with the disk, a fixed stud closely adjacent the dl sk, a lever pivoted to the stud, a second lever pivoted on the stud and adapted to have operative connection with the first named lever when the latter is in low position, friction means carried by the second lever to engage the disk and force the latter against the first named friction when the first lever is down, and means to lift the first named lever as the warp is consumed to break the engagement between the levers and thereby lessen the pressure exerted by the friction means.

2. In a let-off for a narrow ware loom having a warp spool and a disk movable therewith and a friction element to cooperate with the disk, a pair of levers pivotally mounted about a common center which is closely adjacent the disk, said levers being 111 engagement when sufficient warp is present, a fraction surface on one lever to force the dlsk against the first friction element when the other lever is down, and means dependent upon the shortening of the warp to 11ft the last named lever out of operative engagement with the first named lever and thereby d1- minish the friction exerted by the friction surface against the disk.

In a let-off for a narrow ware loom having a warp spool and a disk movable therewith and a friction element to cooperate with the disk, a pair of levers pivotally mounted about a common center which is closely adjacent the disk, said levers being in engagement when sufiicient warp is present, a friction surface on one lever to force the disk against the first friction element when the other lever is down, means dependent upon the shortening of the warp to lift the lastnamed lever out of operative engagement with the first named lever and thereby diminish the friction eX- erted by the friction surface against the disk, and resilient means'interposed between the levers and operative when said other lever moves out of engagement with the first named lever to exert a pressure against the latter.

4. In a let-oif for a'narrow ware loom having a warp spool and a disk movable therewith and a friction element to cooperate with the disk, a pair'of levers pivotally mounted about a common center which is closely adjacent the disk, means to establish engagement between the levers when one lever is down, a friction member on the other lever toforce the disk against the friction element when said first lever is down, and means dependent upon the shortening of the warp to lift the first llO named lever out of operative engagement with the other lever and thereby diminishthe friction exerted by the friction member against the disk, and resilient means interposed between the levers and operative when the first lever moves out of engagementwith the second lever to exert a pressure against the latter, the pressure diminishing as the first named lever moves upwardly.

5. In a let-off for a narrow'ware loom hav-t ring a-rwarp spool and a disk movable therewith and a friction element'to cooperate with the disk, a pair of levers pivotally mounted about a common center, means to establish engagement between the levers when one lever is down, a friction member on the other lever to force the diskagainst the friction element when said first lever is down, and means dependent upon the shortening of the warp to lift the first named lever out of operative engagement with the other lever and thereby.

diminish the friction exerted by the friction member against the disk, and yielding means interposed between the levers and operative when the firstlever moves out of engagement with the second lever to exert a pressure against the latter, the pressure diminishing as the first named lever moves upwardly;

6. In a let-off for narrowware looms, a

warp beam, a disk rotatable therewith, a pair of friction element-s between whichthe disk lies, a pair of pivoted members one of which carries one of the friction elements and the other of which carriesthe other friction element and is determined as to position by the tension of the warp, andyieldingmeans between the members, themembers normally being in operativeengagement with eachother when sufficient warp has been unwound, and moving out of operative engagement with each other when insufficient warp remains, the yielding means operating to hold the friction pad against the disk when the members are out of operative engagement.

7. In a let-off for narrow ware looms, a

, warp beam, a disk rotatable therewith, a pair of friction elements between which the disk moves, ajpair of pivoted members one of which carries one of the friction elements and the other of which carries the other friction element and is determined as to position byv the tension of the warp, and yielding means between the member, the members normally being in -operat1ve engagement with each other when suflicient warp has'been unwound" and moving out of operative engagement with each other when insufficient warp remains,

' the yielding means operating to hold the fric- V which diminishes as said other member moves upwardly.

tion pad against the disk when the members are out of operative engagement with a force In testimony fixed mysignature.

' ELBRIDGE R; HOLMES.

hereof I have hereunto af 

